This invention relates to clutch drive mechanisms adapted to engage axially moveable, driven clutch plates in motor vehicles. More particularly, the invention relates to heavy-duty clutches of the type having a flywheel drivingly coupled to an intermediate driven plate for transmission of torque to the plate.
Prior art drive mechanisms for intermediate clutch plates have endured limited success in accommodating misalignments between plate and flywheel members. Most incorporate drive heads of various configurations which extend radially inwardly from the flywheel for rigid engagement with a drive slot of the intermediate plate. One newer design, however, permits a drive head to swivel or rotate on a drive pin which extends from the flywheel for registration of the head with the intermediate plate slot. Although the latter offers greater accommodation for misalignment than do the "fixed" head designs, there remains room for improvement with respect to both installation and operating performance.
For example, the drive pin lacks a positive mechanical stop upon its being press-fitted into a receiving bore in the clutch flywheel, thus requiring special precautions against over-insertion. Moreover, upon mounting the drive head on the pin, there is no provision for assuring clearance between the drive head and the internal surface of the flywheel. Such clearance avoids contact between drive head and flywheel members, and thus is necessary to assure interference-free swivel of the drive head.
Finally, the actual shape of the drive head does not lend itself to ease of installation of the intermediate plate. Thus, there remains a need to redesign the head to more readily engage an intermediate plate drive slot.